Bug 1472955 – DWARF5 support in readelf

Bugzilla will be upgraded to version 5.0 on a still to be determined date in the near future. The original upgrade date has been delayed.

Bug 1472955 - DWARF5 support in readelf

Summary:	DWARF5 support in readelf

Status:	CLOSED ERRATA

Aliases:	None

Product:	Red Hat Enterprise Linux 7
Classification:	Red Hat
Component:	binutils (Show other bugs)
Sub Component:
Version:	7.5
Hardware:	Unspecified Unspecified

Priority	unspecified Severity unspecified
Target Milestone:	rc
Target Release:	---
Assigned To:	Nick Clifton
QA Contact:	Miloš Prchlík
Docs Contact:	Vladimír Slávik

URL:
Whiteboard:
Keywords:

Depends On:
Blocks:	1471969 1472966 1472969 1472971 1472978 1472979
	Show dependency tree / graph

Reported:	2017-07-19 12:29 EDT by Ben Woodard
Modified:	2018-04-10 06:00 EDT (History)
CC List:	8 users (show)

See Also:
Fixed In Version:	binutils-2.27-10.base.el7
Doc Type:	Enhancement
Doc Text:	Improved DWARF 5 support in various tools Support for the DWARF debugging format version 5 has been extended in the following tools: * The `eu-readelf` tool from the _elfutils_ package now recognizes all DWARF 5 tags and attributes. * The `readelf` and `objdump` tools from the _binutils_ package now recognize the DWARF 5 tag `DW_AT_exported_symbols` and correctly report its presence in debug information sections.
Story Points:	---
Clone Of:
Clones:	1472966 1472969 1472978 1496220 (view as bug list)
Environment:
Last Closed:	2018-04-10 05:59:05 EDT
Type:	Bug
Regression:	---
Mount Type:	---
Documentation:	---
CRM:
Verified Versions:
Category:	---
oVirt Team:	---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---

Attachments	(Terms of Use)
clang compiled object that includes the example above (45.27 KB, application/x-object) 2017-07-19 12:29 EDT, Ben Woodard	no flags	Details
Add an attachment (proposed patch, testcase, etc.)

External Trackers
Tracker	ID	Priority	Status	Summary	Last Updated
Sourceware	20755	None	None	None	2017-07-19 13:44 EDT
Red Hat Product Errata	RHBA-2018:0686	None	None	None	2018-04-10 06:00 EDT

Groups: None (edit)

Description Ben Woodard 2017-07-19 12:29:29 EDT

Created attachment 1301240 [details]
clang compiled object that includes the example above

Description of problem:
We are starting to use Clang 4.0.0 at LLNL and it is emitting some DWARF5 opcodes. Please backport DWARF5 decoding to RHEL's binutils.

For example:
#include <string>
#include <vector>

std::vector<std::string> var;

and tangentially I saw something in the DWARF which neither readelf or eu-readelf understands.

<2><7e1>: Abbrev Number: 23 (DW_TAG_namespace)
    <7e2>   DW_AT_name        : (indirect string, offset: 0x15c): __cxx11
    <7e6>   DW_AT_decl_file   : 1
    <7e7>   DW_AT_decl_line   : 2214
    <7e9>   Unknown AT value: 89: 1

probably a rebase is too dangerous and the changes haven't even landed in 2.28 yet. However, since clang is already emitting some DWARF5 we should at least be able to decode what it is emitting reliably.

Comment 2 Nick Clifton 2017-07-20 05:36:41 EDT

Hi Ben,

  Unfortunately this request has arrived too late to be included into RHEL 7.4.
  I will make sure however that the RHEL 7.5 binutils does contain the required
  patch.

  In the meantime you might want to consider using the soon-to-be-released
  Developer Toolset 7 for RHEL 7.4, as I have patched those sources as well.

Cheers
  Nick

Comment 3 Nick Clifton 2017-08-09 08:35:08 EDT

The fix has now been added to the RHEL-7.5 binutils branch.

Comment 6 Nick Clifton 2017-12-05 10:09:57 EST

Hi Vladimír,

  Looks good to me. :-)

Cheers
  Nick

Comment 8 Miloš Prchlík 2018-02-01 03:59:01 EST

Verified with binutils-2.27-9.base.el7.

Comment 11 errata-xmlrpc 2018-04-10 05:59:05 EDT

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2018:0686

Note You need to log in before you can comment on or make changes to this bug.